REV. 0

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a

ADM809-5S/L

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.

Tel: 781/329-4700

World Wide Web Site: http://www.analog.com

Fax: 781/326-8703

© Analog Devices, Inc., 2000

Microprocessor

Supervisory Circuit

FUNCTIONAL BLOCK DIAGRAM

RESET

GENERATOR

55ms

ADM809-5S/L

RESET

GND

FEATURES

Specified Over Temperature

Low Power Consumption (17

A)

Precision Voltage Monitor: 3 V, 5 V Options

30 ms min Power-On Reset

Logic Low

RESET Output

APPLICATIONS

Microprocessor Systems

Computers

Controllers

Intelligent Instruments

Automotive Systems

GENERAL DESCRIPTION

The ADM809-5S/L supervisory circuits monitor the power

supply voltage in microprocessor systems. It provides a reset

output during power-up, power-down and brownout conditions.

On power-up, an internal timer holds reset asserted for 55 ms.

This holds the microprocessor in a reset state until conditions

have stabilized. The

RESET output remains operational with

reset signal (

RESET).

The reset comparator features built-in glitch immunity,

The ADM809-5S/L consumes only 17

µA, making it suitable

for low power portable equipment.

RESET

RESET

INPUT

GND

GND

P

SYSTEM

ADM809-5S/L

Figure 1. Typical Operating Circuit